7.  Troubleshooting

      There are several messages that may be generated by the the line printer system. This section categorizes the most common and explains the cause for their generation. Where the message implies a failure, directions are given to remedy the problem.

      In the examples below, the name printer is the name of the printer from the printcap database.

7.1.  LPR

lpr: printer: unknown printer

• The printer was not found in the printcap database. Usually this is a typing mistake; however, it may indicate a missing or incorrect entry in the /etc/printcap file.

lpr: printer: jobs queued, but cannot start daemon.

• The connection to lpd on the local machine failed. This usually means the printer server started at boot time has died or is hung. Check the local socket /dev/printer to be sure it still exists (if it does not exist, there is no lpd process running). Usually it is enough to get a super-user to type the following to restart lpd.

  % /usr/lib/lpd
  

  You can also check the state of the master printer daemon with the following.

  % ps l`cat /usr/spool/lpd.lock`
  

• Another possibility is that the lpr program is not set-user-id to root, set-group-id to group daemon. This can be checked with

  % ls -lg /usr/ucb/lpr
  

lpr: printer: printer queue is disabled

• This means the queue was turned off with

  % lpc disable printer
  

  to prevent lpr from putting files in the queue. This is normally done by the system manager when a printer is going to be down for a long time. The printer can be turned back on by a super-user with lpc.

7.2.  LPQ

waiting for printer to become ready (offline ?)

• The printer device could not be opened by the daemon. This can happen for several reasons, the most common is that the printer is turned off-line. This message can also be generated if the printer is out of paper, the paper is jammed, etc. The actual reason is dependent on the meaning of error codes returned by system device driver. Not all printers supply enough information to distinguish when a printer is off-line or having trouble (e.g. a printer connected through a serial line). Another possible cause of this message is some other process, such as an output filter, has an exclusive open on the device. Your only recourse here is to kill off the offending program(s) and restart the printer with lpc.

printer is ready and printing

• The lpq program checks to see if a daemon process exists for printer and prints the file status located in the spooling directory. If the daemon is hung, a super user can use lpc to abort the current daemon and start a new one.

waiting for host to come up

• This implies there is a daemon trying to connect to the remote machine named host to send the files in the local queue. If the remote machine is up, lpd on the remote machine is probably dead or hung and should be restarted as mentioned for lpr.

sending to host

• The files should be in the process of being transferred to the remote host. If not, the local daemon should be aborted and started with lpc.

Warning: printer is down

• The printer has been marked as being unavailable with lpc.

Warning: no daemon present

• The lpd process overseeing the spooling queue, as specified in the ``lock'' file in that directory, does not exist. This normally occurs only when the daemon has unexpectedly died. The error log file for the printer and the syslogd logs should be checked for a diagnostic from the deceased process. To restart an lpd, use

  % lpc restart printer
  

no space on remote; waiting for queue to drain

• This implies that there is insufficient disk space on the remote. If the file is large enough, there will never be enough space on the remote (even after the queue on the remote is empty). The solution here is to move the spooling queue or make more free space on the remote.

7.3.  LPRM

lprm: printer: cannot restart printer daemon

• This case is the same as when lpr prints that the daemon cannot be started.

7.4.  LPD

      The lpd program can log many different messages using syslogd(8). Most of these messages are about files that can not be opened and usually imply that the printcap file or the protection modes of the files are incorrect. Files may also be inaccessible if people manually manipulate the line printer system (i.e. they bypass the lpr program).

      In addition to messages generated by lpd, any of the filters that lpd spawns may log messages using syslogd or to the error log file (the file specified in the lf entry in printcap).

7.5.  LPC

couldn't start printer

• This case is the same as when lpr reports that the daemon cannot be started.

cannot examine spool directory

• Error messages beginning with ``cannot ...'' are usually because of incorrect ownership or protection mode of the lock file, spooling directory or the lpc program.